Risk

Risk is concerned with the unknown. Upside risk is the possibility of gain. Downside risk is the possibility of loss. One half the reasons to use options (like other derivatives) is to reduce risk. Certainty is exchanged with other players who assume the risk in hope of big gains. It is wrong to state that "options are risky."

reduce risk: The seller of a covered call exchanges his upside risk (gains above the strike price) for the certainty of cash in hand (the premium). The buyer of a covered put limits his downside risk for a price - just like buying fire insurance for your house.

increase risk: The buyer of a call wants the upside risk of an asset, but will only pay a small percentage of its current value, so his returns are leveraged. The seller of a put accepts the downside risk of locking in his purchase price of an asset, in exchange for the premium.

To understand risk, look at the four standard graphs of options (put-call-buy-sell). The value of the options in the interim between purchase and expiration will not be exactly like these graphs, but close enough. In all cases, the premium was a certainty.

Buyers start out-of-pocket. But going forward, the option buyer has no downsider risk. The graph either flat lines or goes up on either side of the spot price.

Sellers start with a gain. Going forward, they have no upside risk. These graphs either flat line or go down on either side of the spot price.

The extent of risk varies. Buyers/sellers of calls have unlimited upside/downside risk as the asset price increases. Buyers/sellers of puts have upside/downside risk limited to the spot price of the asset (less the premium).